Electronic devices for personal use have been miniaturised to enable portability, thereby enhancing utility and functionality for devices such as laptops, cellphones, calculators, handheld organisers, portable radios, or CD players as well as other similar devices. Sufficient miniaturisation has made it possible to integrate electronics into everyday items, such as clothing.
Many articles of clothing have now been made to incorporate pockets for carrying devices like cellphones, compact disc players, and portable audio players or other electronic equipment.
From prior art, the concept of a “wearable computer” is well-known, such a wearable computer comprising a powerful, yet very small and ergonomically designed computer system that can be worn by the user over extended periods of time, usually kept at or on the clothing. It is desirable to integrate the small electronic devices and/or the wearable computer along with its periphery devices with textiles and garments, dramatically increasing the functionality and portability of the devices. Hands-free operation is a goal of many of these efforts.
For certain advanced functions, personal electronic devices and/or wearable computers may be equipped with various sensors which have preferably or intrinsically to be worn on the body of the user, e.g. for detecting the pulse frequency, the ECG waveform, respiration, footstep rate or other parameters of the user.
On the one hand, in such cases the output signals of such sensors need to be transmitted from the inner side of a garment to electronic devices and/or wearable computers located outside of the garment. Such sensors are of particular importance in conjunction with certain kinds of professional clothing, e.g. protective clothing for fire-fighters or protective uniforms for military personnel. However, it should be clear that the use of sensors is not limited to such kinds of protective clothing as there are other fields of application e.g. for outdoor leisure clothing, etc.
On the other hand, intelligent sensors or other electronic devices located at the inner side of the garment may need to be fed with control data or the like from a computer located at the outer side of the garment.
Hence, for advanced solutions, a bidirectional data transfer between some kind of apparatus located on the outer side of the garment and other components located on the inner side of the garment is desirable.
In many cases, the electronic components located on the inner side of the garment may need some form of electrical power supply. This can be done by providing a separate battery or accumulator nearby or at the respective electronic components; however, it would clearly be advantageous to provide an electrical power supply through the same means provided for data transfer in order to reduce system complexity and costs.
Another important aspect of modern garments relates to the technical properties in respect of permeability for liquid water and water vapour. In particular with regard to outdoor applications, garments should be waterproof. For advanced applications, however, water vapour should be able to pass through in order to enhance the comfort of wearing of such textiles by avoiding or at least reducing the moistening of the skin of a user with sweat. There are various enhanced textile materials known comprising some sort of membrane (e.g. made of microporous polytetrafluoroethylene PTFE) which is permeable for water vapour but impermeable for water in the liquid form.
When establishing the path for delivery of electrical power and/or data signals from at least one electronic device mounted on the outer side of a garment to a sensor or another electronic component mounted on the inner side of the garment, a solution is needed for the problem of passing data and/or electricity through the textile of the garment. In cases where a waterproof garment is to be used, precautions must be taken in order to make sure that any electronic facilities for data and/or electrical power transmission will not harm the waterproof properties of the garment.
From U.S. Pat. No. 6,324,053 B1, a system and method for the electrical interconnection of devices included in a wearable computer or in a similar system have come to be known. A power supply and data network are formed by attaching to clothing, as stitches, an extremely fine conductive wire that is used to connect devices included in a wearable computer wherein an I/O device and a computer system main body are separately located.
The network as disclosed by said U.S. Pat. No. 6,324,053 B1 is, taken as such, suited for connecting sensors or other electronic components mounted on the inner side of a certain garment with a wearable computer or with other electronic devices mounted on the outer side of an electronic garment. However, introducing a fine conductive wire as stitches means that such an attempt is in particular incompatible with providing a waterproof but vapour-permeable garment equipped with a membrane. Such a membrane would inevitably be pierced many times by the stitches necessary for setting up the network, creating undesirable water bridges. Practical experience has shown that it is very difficult to close such water bridges along the stitches. Moreover, the fine wires provide a galvanic coupling which might cause electrical problems such as an electrical hazard or poor electrical properties.
From patent application WO 01/45038 A2, a short range communication system has come to be known. In a particular implementation thereof an interrogator held near a person interrogates multiple transponders and receives information separately from the transponders. The interrogator and/or the transponders may be held in an article of clothing or in an item of baggage of the person. Such a system enables the clothes worn by a person to communicate with a plurality of items e.g. for obtaining useful information. In principle, a short range communication system known from patent application WO 01/45038 A2 can also be used for transmitting sensor data from a sensor mounted on the inner side of the garment through the (textile) material thereof to any electronic device or wearable computer mounted on the outer side of the garment without any piercing of the garment.
However, in a number of cases the user of wearable computers or other comparable electronic devices for personal use must be protected against eavesdropping by exploitation of outbound compromising electromagnetic emanations as well as against disturbances caused by electromagnetic interference (EMI) of inbound electromagnetic radiation of the environment, in particular caused by strong electromagnetic pulses (EMP).
This is in particular relevant with regard to military applications; to some degree these requirements are also to be met e.g. with regard to professionals like fire-fighters etc.
Moreover, a pure radio-based solution is not suitable for providing electronic components located at the inner side of the garment with a substantial amount of electrical power provided at the outer side of the garment. There are also concerns about the biological hazards which perhaps might be caused by the exposure of living tissue to relatively strong fields of high frequency electromagnetic radiation which would be necessary for an effective transmission of electrical power by a high frequency electromagnetic field.
Hence, although wireless connectivity may provide suitable advantages, there are fields of application where the interconnection of electronic devices for personal use and/or a wearable computer with their periphery by means of (preferably shielded) electric wires might be preferred over wireless solutions.
Providing a connecting wire intersecting the textile material forming the garment is, however, very problematic in any cases where waterproof properties are critical.
Hence, there is a strong need for providing an advanced garment being equipped with facilities for interconnecting electronic devices amongst each other and/or a wearable computer with its related periphery, whereby electrical power supply and/or data paths have to be provided through the textile material without the need to pierce the material forming the garment or, at least, where the boundaries of the material forming the garment can reliably be made waterproof.